Drug interactions
Citalopram + Metolazone
Severity: Moderate
Citalopram and Metolazone: moderate interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Both thiazide-like diuretics and SSRIs can cause hyponatremia, and combined use raises the risk, especially in older adults. Hypokalemia and hypomagnesemia from metolazone may also add to citalopram's QT-prolonging risk.
What this interaction means in plain words
Citalopram and Metolazone can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Citalopram belongs to Central Nervous System; Metolazone belongs to Cardiovascular.
Why it happens
Additive hyponatremia from diuretic sodium loss and SSRI-associated inappropriate ADH secretion; electrolyte disturbances may potentiate QT prolongation.
What to do
Check serum sodium, potassium and magnesium at baseline and after starting, especially in older patients, and correct deficits. Consider ECG monitoring if electrolytes are abnormal or other QT-prolonging drugs are used.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Metolazone
Other interactions of Citalopram
- Cisapride + Citalopram Contraindicated
- Citalopram + Dronedarone Contraindicated
- Citalopram + Escitalopram Contraindicated
- Citalopram + Isocarboxazid Contraindicated
- Citalopram + Methylene blue Contraindicated
- Citalopram + Phenelzine Contraindicated
Frequently asked questions
Can I take Citalopram with Metolazone?
MediHelp rates the interaction as moderate. Citalopram and Metolazone can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Both thiazide-like diuretics and SSRIs can cause hyponatremia, and combined use raises the risk, especially in older adults. Hypokalemia and hypomagnesemia from metolazone may also add to citalopram's QT-prolonging risk.
How serious is the interaction between Citalopram and Metolazone?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Check serum sodium, potassium and magnesium at baseline and after starting, especially in older patients, and correct deficits. Consider ECG monitoring if electrolytes are abnormal or other QT-prolonging drugs are used.
What other medicines interact with Metolazone?
MediHelp also lists interactions of Metolazone with, for example, Amifostine, Amlodipine-hydrochlorothiazide-valsartan, Amlodipine-olmesartan-hydrochlorothiazide. The full list is on the Metolazone page.
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